MONDAY, Jan. 8, 2018 (HealthDay News) -- The United States has had the smallest decline in child death rates among wealthy nations over the past 50 years, despite spending more on health care per child than the other countries, a new study finds.

Researchers analyzed child death rates from 1961 to 2010 in the United States and 19 other economically similar countries, including Canada, Australia, Germany, Italy and Switzerland.

All of the countries registered a reduction in the death rate among children. But the rate in the United States has been slowest to decline and has been higher than in the other 19 countries since the 1980s, the findings showed.

Over the 50-year study period, the slower reduction in the U.S. child death rate has resulted in more than 600,000 excess deaths, according to the study.

In all of the countries, about 90 percent of child deaths occurred among infants and older teens (aged 15 to 19). In the most recent decade studied (2001-2010), U.S. infants were 76 percent more likely to die and children aged 1 to 19 were 57 percent more likely to die than their counterparts in other wealthy nations.

Leading causes of infant death during the most recent decade were premature births and sudden infant death syndrome (SIDS). Compared with babies in other countries in the study, U.S. children were three times more likely to die because of premature birth and more than twice as likely to die from SIDS, the study found.

In the United States, the two leading causes of death for teens aged 15 to 19 were motor vehicle crashes and gun violence. Compared with teens in the other wealthy nations, American teens were twice as likely to die from motor vehicle crashes and 82 times more likely to die from gun violence.

"Overall child mortality in wealthy countries, including the U.S., is improving, but the progress our country has made is considerably slower than progress elsewhere," said the study's lead author, Dr. Ashish Thakrar. He is an internal medicine resident at Johns Hopkins Hospital in Baltimore.

"Now is not the time to defund the programs that support our children's health," Thakrar added in a news release from Johns Hopkins Medicine.

While the United States spends more per child on health care than other wealthy nations, it has poorer outcomes than many, Thakrar noted. It ranked 25th among 29 developed countries for overall child health and safety on a list put out by the United Nations Children's Fund.

Dr. Christopher Forrest, a pediatrician at Children's Hospital of Philadelphia and the study's senior author, said, "The findings [of the new study] show that, in terms of protecting child health, we're very far behind where we could be."

Forrest added, "We hope that policymakers can use these findings to make strategic public health decisions for all U.S. children to ensure that we don't fall further behind peer nations."

The researchers concluded that U.S. politicians need to fully fund the Children's Health Insurance Program (CHIP), which provides health insurance to millions of disadvantaged children, and the Supplemental Nutrition Assistance Program (SNAP), which provides food stamps.

In addition, public health research and programs can help reduce the death toll from gun violence and car crashes among U.S. children, the study authors said.